Matrix™ is a highly porous media designed to provide exceptionally efficient biofiltration for single site removal of ammonia, nitrite, and nitrate from freshwater, marine, and reef aquaria. Each liter of Matrix™ provides over 160,000 cm2 (170 sq. ft.) of surface, equivalent to over 40 L (10 gallons) of typical plastic ball media! DIRECTIONS: Use 500 mL of Matrix™ for each 200 L (50 gallons*) of water. Matrix™ may be placed in any kind of filter, and is particularly effective in a canister filter. Matrix™ is sufficiently large that no filter bag should be required for most applications. Matrix™ works well in drip tray systems, but you may find that the larger Pond Matrix™ is better suited for such applications.